标题：Factors that Affect the Species Richness of the Raptor Guild of the Carnivore Community in the Afro-Alpine Sections of the Bale Mountains National Park (BMNP)
摘要：The Afro-alpine moorlands of the Bale Mountains National Park (BMNP) constitute a diverse guild ofavian carnivores. The response of the species richness of this guild to ecological processes isevaluated in this paper. Importance of elevation, topographic physical features, patch heterogeneity ofhabitat and prey were evaluated in explaining the species richness of the guild of diurnal raptors. Thespatial variation in the moorland ecosystem as result of associations of these explanatory processvariables was determined through a Principal Component Analysis. This showed there were threespatial clusters of census patches that held significantly different number of species of the guild.Importance of the variables that defined the spatial variability of the ecosystem in explaining thechanges in the species richness of the raptor guild was explored through simple correlation analysesand step-wise multiple linear regression that made use of PCA components of covarying explanatoryvariables. The first axes of the PCA mainly defined by elevation, patch physical features, habitatheterogeneity, diversity of relatively small birds and relatively large sized avian and mammalian preywas selected as a significant predictor. In this model, species richness responded negatively to theenvironmental variables. Heterogeneity of patches in vegetation type and species richness of preycommunities that included birds and mammals such as hare and hyrax affected the species richnessof the raptors significantly positively. A simple linear regression model showed interspecific nicheoverlap declined as a function of species richness..
